Helpme PTR RECORD & VIRTUALMIN tools administration

I am running debian Buster version 10.6 with virtualmin 6.12. I need to properly configure the dns so that I can have several domains with an spf record, for each domain that points to a PTR record aidin1.mydomain.tld, I must configure many web and email domains and I would like to avoid being listed as spammer …
I would like you to help me by giving me detailed instructions on How to use virtualmin to create domains and that I can also create databases for those domains, and all the functionalities. I don’t have very good English please help me
Operating system: DEBIAN BUSTER
OS version: 10.6